Okay, so the background to this study is really the fact that BTB grafts have widely been considered, especially historically the gold standard for ACL reconstruction. However, there's a misconception that isn't really evidence-based, that if you do a good BTB graft, you don't need an extra articular reconstruction, and that's the basic premise behind this study. So our purpose is to compare the clinical outcomes after the theoretical gold standard BTB autograft as an isolated ACL reconstruction versus combined reconstructions with hamstring tendons, so that's an ACL reconstruction plus ALL reconstruction. The study dates were between January 2003 and 2019, and during that time period, Bertrand performed over 6,000 primary ACL reconstructions. So one of the advantages of this study is that it's the largest study on the topic, and also because of the volume of patients that we had, we were able to do a propensity match study. So I won't go through all the exclusion criteria, but at the end of the day, we had 1,000 patients in each group. We matched them according to age, gender, BMI, participation in pivoting sports, contact sports, and their pre-injury Tegna score, and as you can see on the right-hand side, as we would expect with such a large study population, the two groups were well matched. In terms of the surgical technique for the combined reconstruction, we harvested gracilis and semitendinosus tendons. The ACL portion of this graft is combined of a tripled semitendinosus and an additional strand of gracilis, so it's a four-strand graft. That additional length of gracilis goes on to form the ALL reconstruction. On the right-hand side, you can see that it's brought out just proximal and posterior to the lateral epicondyle and then shuttled through a tibial tunnel to replicate the normal anatomy of the ALL as best as possible. Post-operatively, both groups underwent exactly the same rehabilitation. All patients underwent AP cytoside laxity assessment at one year post-operatively, and then our final follow-up was defined by their last recorded appointment date prior to January 2022. We reviewed their medical records and our database to determine the graft rupture rate and reoperations for non-graft rupture-related indications. At one-year follow-up, there was no significant difference in the groups in terms of AP cytoside laxity difference. However, there was a significant difference between the groups with respect to the mean duration of follow-up. Obviously, this study spanned 16 years, and extra-articular procedures are much more common now, so it's unsurprising that in our combined reconstruction group, the mean follow-up was 65 months compared to 136 in the BTB group. For that reason, we used time-to-event data analyses so that they were independent of differences in mean follow-up between the groups. So we used multivariate Cox analysis, and in that, we demonstrated the main finding of this study that if you have an isolated ACL reconstruction with a BTB graft, your risk of graft failure is three times higher than if you have a combined reconstruction. We also looked at that by each individual time point listed there below, so 24, 36, and 65 months, and I won't go through all the individual data there, but you can see that at each time point, there was a significant advantage for combined reconstructions. We also looked at this in Kaplan-Meier analysis, so on the left-hand side, you can see our overall study population, again, three-fold higher risk of graft failure with a BTB reconstruction. However, BTB grafts are particularly indicated for our young, active patients in the high-risk category, and so we did a specific analysis in that population, which you can see on the right-hand side, and that also demonstrated a significant advantage for combined reconstructions in that particular high-risk group, again, three-fold advantage to combined reconstructions. Overall, so that means including graft rupture and non-graft rupture-related re-operations, the risks were higher in the isolated BTB group. Additional significant differences were with respect to re-operation for Cyclops lesion, which is unsurprising. We've known for a long time that extension deficits and re-operation for Cyclops is more common with BTB grafts than other soft-tissue grafts. The other finding was that secondary meniscectomy was much more common with BTB, and that's also unsurprising because we've previously published on this topic and demonstrated that if you have a medial meniscus repair at the time of your ACL reconstruction and you have an ALL reconstruction, the re-operation rate for a secondary meniscectomy is two-fold reduced, and we believe that's because we can better restore the normal knee kinematics so there's less abnormal loading on that repaired meniscus. Overall, our results are also in keeping with the previous literature. Here's a forthcoming systematic review from our group, and you can see here that almost every single previous study on this topic comparing isolated versus combined reconstructions shows an advantage, or at least a trend towards an advantage, for combined reconstructions. So in conclusion, isolated BTB reconstructions are associated with a three-fold higher rate of graft rupture than combined reconstructions, and also with significantly higher rates of non-graft rupture-related re-operations. Thank you.

ACL reconstruction surgeries

BTB autografts

hamstring tendons

graft failure

combined reconstructions